Intraepithelial tumors – Bowen's disease which originates from glandular cells in the skin

Keratocanthomas – originate in the epidermis

The skin is the body's largest organ and weighs about 2 kg in a 70 kg person. For an adult, the surface is between 1.5 and 2.2 m2. The skin consists of three layers: the epidermis, dermis, and subcutaneous layer, all of which can develop cancer. The histological subtype depends on which of the different cell layers are malignant.

Skin types

The separation of skin types is based on sensitivity to sun rays, especially UV rays. In Norway, the most common skin types are 1–4.

Nonmelanoma skin cancer - Essential facts

Incidence

Of nonmelanoma skin cancer, basal cell carcinoma (BCC) has not been reported to the Cancer Registry of Norway since it does not spread like other cancers. It is estimated that there are about 12,000 new lesions each year. Of squamous cell carcinoma (SCC), there were 1884 cases registered in 2015 in Norway, 1044 men and 840 women. All of the other subgroups are considerably more rare. Between 5 to 20 cases occur annually.